When to Plant Parsley in DuPage County, IL
Your May gardening checklist
Here's what deserves your attention in DuPage County, Illinois this month. Everything below is tailored to Zone 5b and timed around your local frost dates.
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Time to start parsley inside
Your window is short. These crops want several weeks of indoor growth before they go outside.
Before June arrives, get these ready
- First harvests: parsley
Parsley is a biennial herb available in flat-leaf (Italian) and curly varieties. It is a nutritional powerhouse rich in vitamins C and K and adds fresh flavor to countless dishes.
DuPage County, Illinois is in USDA Zone 5b. The average last spring frost is April 23 and the first fall frost is October 17, giving you a growing season of approximately 177 days.
At an elevation of 803 feet, DuPage County receives approximately 31 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Parsley to ensure they mature before fall.
DuPage County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.7
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in DuPage County
How your county's soil matches Parsley's growing requirements.
Soil pH
Your soil pH (6.0–6.7) is within Parsley's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in DuPage County is excellent for Parsley — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.0%) — Parsley will thrive.
How to Plant Parsley
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Parsley
Sow every 6.9 weeks. Last sowing by Jul 29 to harvest before frost.
For a dedicated fall crop, sow by Aug 08.
Plant Water Budget
Monthly Watering Guide for Parsley
Parsley needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Parsley Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | 2.6" | 3" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 2.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3.7" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 2.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.2" | 0.4" | 💧 Light watering |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 1.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in DuPage County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Parsley Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Parsley Planting Timeline — DuPage County, IL
Parsley Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 19 | Mar 19 – Apr 2 |
| Transplant Outdoors | April 16 | Apr 16 – Apr 30 |
| Direct Sow | April 9 | Apr 9 – Apr 30 |
| Harvest | June 18 | Jun 18 – Aug 20 |
| Fall Sowing | August 8 | Aug 8 – Aug 22 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
177 days in DuPage County
Growing Tips for Parsley in DuPage County
Direct sow Parsley outdoors after April 23 in DuPage County when soil has warmed and frost danger has passed.
Common pests for Parsley in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 6-8 weeks before last frost. Soak seeds overnight as germination is slow. Harvest outer stems first to keep plants productive. Parsley attracts swallowtail butterflies.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Parsley in Other Locations
Frequently Asked Questions
When should I plant Parsley in DuPage County, IL?
DuPage County is in Zone 5b with an average last frost of April 23. Plan your Parsley planting based on this frost date — see the calendar above for exact timing.
What planting zone is DuPage County, IL?
DuPage County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 23 and first fall frost is October 17.
Your DuPage County Garden Planner — Free
A 24-page printable planner built for DuPage County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.